STEVENS, J., dissenting tive volume of sound leaving the booth, which presumably was discernible in the public domain. Surely, there is a significant difference between the general and well-settled expectation that strangers will not have direct access to the contents of private communications, on the one hand, and the rather theoretical expectation that an occasional homeowner would even care if anybody noticed the relative amounts of heat emanating from the walls of his house, on the other. It is pure hyperbole for the Court to suggest that refusing to extend the holding of Katz to this case would leave the homeowner at the mercy of "technology that could discern all human activity in the home." Ante, at 35–36. Second, the Court argues that the permissibility of "through-the-wall surveillance" cannot depend on a distinction between observing "intimate details" such as "the lady of the house [taking] her daily sauna and bath," and noticing only "the nonintimate rug on the vestibule floor" or "objects no smaller than 36 by 36 inches." Ante, at 37, 3839. This entire argument assumes, of course, that the thermal imager in this case could or did perform "through-thewall surveillance" that could identify any detail "that would previously have been unknowable without physical intrusion." Ante, at 39-40. In fact, the device could not, see n. 1, supra, and did not, see Appendix, infra, enable its user to identify either the lady of the house, the rug on the vestibule floor, or anything else inside the house, whether smaller or larger than 36 by 36 inches. Indeed, the vague thermal images of petitioner's home that are reproduced in the Appendix were submitted by him to the District Court as part of an expert report raising the question whether the device could even take "accurate, consistent infrared images" of the 6 The use of the latter device would be constitutional given Smith v. Maryland, 442 U. S. 735, 741 (1979), which upheld the use of pen registers to record numbers dialed on a phone because, unlike "the listening device employed in Katz . . . pen registers do not acquire the contents of communications." STEVENS, J., dissenting outside of his house. Defendant's Exh. 107, p. 4. But even if the device could reliably show extraordinary differences in the amounts of heat leaving his home, drawing the inference that there was something suspicious occurring inside the residence-a conclusion that officers far less gifted than Sherlock Holmes would readily draw-does not qualify as "through-the-wall surveillance," much less a Fourth Amendment violation. III Although the Court is properly and commendably concerned about the threats to privacy that may flow from advances in the technology available to the law enforcement profession, it has unfortunately failed to heed the tried and true counsel of judicial restraint. Instead of concentrating on the rather mundane issue that is actually presented by the case before it, the Court has endeavored to craft an all-encompassing rule for the future. It would be far wiser to give legislators an unimpeded opportunity to grapple with these emerging issues rather than to shackle them with prematurely devised constitutional constraints. I respectfully dissent. [Appendix to opinion of STEVENS, J., follows this page.] Appendix to opinion of STEVENS, J. APPENDIX TO OPINION OF STEVENS, J. (Images and text reproduced from defendant's exhibit 107) Top left: Infrared image of a video frame from the videotape submitted as evidence in this case. The thermogram indicates the suspect house as it appeared with the Gain and contrast in its default setting. Only the outline of the house is visible. The camera used was the Thermovision 210. Top Right: Infrared image of a subsequent videoframe taken from the videotape. The gain and contrast settings have been increased in order to make the walls and roof of the structure appear hotter than what it actually is. Bottom Left: Infrared image of the opposite side of the suspects house. The thermogram is also taken from the same videotape. The camera settings are in the default mode and the outline of the house is barely visible. Only the hot electrical transformer and the street light are identifiable. Bottom Right: The same image, but with the gain and contrast increased. This change in camera settings cause any object to appear hotter than what it actually is. The arrow indicates the overloading of an area immediately around a hot object in this case the electrical transformer and the streetlight. This overloading of the image is an inherent design flaw in the camera itself. Syllabus TUAN ANH NGUYEN ET AL. v. IMMIGRATION AND NATURALIZATION SERVICE CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE FIFTH CIRCUIT No. 99-2071. Argued January 9, 2001-Decided June 11, 2001 Petitioner Tuan Anh Nguyen was born out of wedlock in Vietnam to a Vietnamese citizen and copetitioner Joseph Boulais, a United States citizen. Nguyen became a lawful permanent United States resident at age six and was raised by Boulais. At age 22, Nguyen pleaded guilty in a Texas state court to two counts of sexual assault on a child. Subsequently, respondent Immigration and Naturalization Service initiated deportation proceedings against him based on his serious criminal offenses. The Immigration Judge ordered him deportable. Boulais obtained an order of parentage from a state court while Nguyen's appeal was pending before the Board of Immigration Appeals, but the Board dismissed the appeal, rejecting Nguyen's citizenship claim because he had not complied with 8 U. S. C. § 1409(a)'s requirements for one born out of wedlock and abroad to a citizen father and a noncitizen mother. On appeal, the Fifth Circuit rejected petitioners' claim that §1409 violates equal protection by providing different citizenship rules for children born abroad and out of wedlock depending on whether the citizen parent is the mother or the father. Held: Section 1409 is consistent with the equal protection guarantee embedded in the Fifth Amendment's Due Process Clause. Pp. 59-73. (a) A child born abroad and out of wedlock acquires at birth the nationality status of a citizen mother who meets a specified residency requirement. §1409(c). However, when the father is the citizen parent, inter alia, one of three affirmative steps must be taken before the child turns 18: legitimization, a declaration of paternity under oath by the father, or a court order of paternity. § 1409(a)(4). The failure to satisfy this section renders Nguyen ineligible for citizenship. Pp. 59-60. (b) A gender-based classification withstands equal protection scrutiny if it serves important governmental objectives and the discriminatory means employed are substantially related to the achievement of those objectives. United States v. Virginia, 518 U. S. 515, 533. Congress' decision to impose different requirements on unmarried fathers and unmarried mothers is based on the significant difference between their respective relationships to the potential citizen at the time Syllabus of birth and is justified by two important governmental interests. Pp. 60-71. (1) The first such interest is the importance of assuring that a biological parent-child relationship exists. The mother's relation is verifiable from the birth itself and is documented by the birth certificate or hospital records and the witnesses to the birth. However, a father need not be present at the birth, and his presence is not incontrovertible proof of fatherhood. See Lehr v. Robertson, 463 U. S. 248, 260, n. 16. Because fathers and mothers are not similarly situated with regard to proof of biological parenthood, the imposition of different rules for each is neither surprising nor troublesome from a constitutional perspective. Section 1409(a)(4)'s provision of three options is designed to ensure acceptable documentation of paternity. Petitioners argue that § 1409(a)(1)'s requirement that a father provide clear and convincing evidence of parentage is sufficient to achieve the end of establishing paternity, given the sophistication of modern DNA tests. However, that section does not mandate DNA testing. Moreover, the Constitution does not require that Congress elect one particular mechanism from among many possible methods of establishing paternity, and § 1409(a)(4) represents a reasonable legislative conclusion that the satisfaction of one of several alternatives will suffice to establish the father-child blood link required as a predicate to the child's acquisition of citizenship. Finally, even a facially neutral rule would sometimes require fathers to take additional affirmative steps which would not be required of mothers, whose names will be on the birth certificate as a result of their presence at the birth, and who will have the benefit of witnesses to the birth to call upon. Pp. 62-64. (2) The second governmental interest furthered by § 1409(a)(4) is the determination to ensure that the child and citizen parent have some demonstrated opportunity to develop a relationship that consists of real, everyday ties providing a connection between child and citizen parent and, in turn, the United States. Such an opportunity inheres in the event of birth in the case of a citizen mother and her child, but does not result as a matter of biological inevitability in the case of an unwed father. He may not know that a child was conceived, and a mother may be unsure of the father's identity. One concern in this context has always been with young men on duty with the Armed Forces in foreign countries. Today, the ease of travel and willingness of Americans to visit foreign countries have resulted in numbers of trips abroad that must be of real concern when contemplating the prospect of mandating, contrary to Congress' wishes, citizenship by male parentage subject to no condition other than the father's residence in this country. Equal protection principles do not require Congress to ignore this |